On the Forced Vibration in the Nonlinear Symmetric Structure by Using the Normal Modes

정규모우드를 활용한 비선형 대칭구조물의 강제진동해석

The forced vibration with the symmetric boundary condition in nonlinear structure is studied by utilizing the characteristic of the free vibration which have two modes with the similar natural frequency. Two linear modes exist to have no concern with the amplitude. It is found that the normal mode or elliptic orbit as the newly coupled modes is generated in accordance with changing the stability. It is also known that responses for forced vibration having the small external force and damping are near mode of free vibration and the stability for each response is determined according to the stability for each response is determined according to the stability in mode of free vibration. Finally the stability and bifurcation are analyzed in proportion to increment of external force and damping.